Comet 29P/SW1 was monitored at 230 GHz (BWHM of 22) with the
Swedish European Southern Observatory 15 m antenna during the
whole month of December 1996. CO emission is detected in all averaged
daily runs, providing thus a unique set of observations in which the
line position, width and flux can be measured. The comet was active
at all times and its visual magnitude was of order 16. The CO
production irregularly oscillated between extreme rates that did not
differ in 32 days by more than a factor of . A strong sunward
emission is always present at km/s and shows a strong
peak whose width is very narrow ( km/s), which is indicative
of a very low rotational temperature. The line position and structure
remained remarkably stable. Data accumulated over a period of
sec show the "ON" spectrum with a very high S/N that
allows us to model the 3D structure of the CO cloud. Besides the
main peak exists a skirt that becomes a double peak structure in
offset spectra taken at, respectively, 11 and 22on the sunward
side. These observations allow to fully describe the outgassing
and activity patterns of the nucleus of comet P/SW1 over a one-month
period..